Valve-actuating gear for internal-combustion engines



Dec. 23, 1924. 1,520,208

' G. PlELSTlCK VALVE ACTUATING GEARFOR INTERNAL COMBUSTION ENGINES FiledSept. 8,' 1922 Patented `Der. 2a. 192e.

ortica.

VALVE-ACTUATING GEAR. FOR INTEBNAL-COMBUST-[ON ENGINES.

Application mea septembef a, 1922. serial no. 586,971.

To all lwhom t may concern:

Be it known that I, GUsTAv PIEL-STICK, a citizen of the German Republic,residing at Augsburg, Germany, have invented certain 5 new and usefulImprovements in Valve-Actuating Gears for Internal-CombustionEngines, ofwhich the following is a speciication.

This invention relates to the valve actuating rocking levers of internalcombustion engines and its main object is to-provide a rocking leverwhich will eliminate certain drawbacks existing in the present type ofrocking levers and which consist in the dificulty of adjusting or timingthe valves to suit varying conditions of engine running.

lt is known that hitherto the valves have s been timed by adjustment ofthe valve operating cam and by altering the distance of the cam rollerfrom the cam. In stationary engines this adjustment is eected during theengine test, whereas in marine engines, which, asa rule, do not undergosuch engine tests, adjustment isl carried out during the trial run' ofthe vessel. But even apart from such initial timing it is oftennecessary to alter the timing under normal working conditions when, forexample, after changin the valves, or after changing from one fue toanother, the working diagram of the engine has been altered so thatre-timing is required. At the present time, since this adjustment of thevalves must be carried onv by altering the position of the cam, it isnecessary that the engine be stopped and in the case of marine enginesthis involves stopping the ship. Furthermore, this adjustment'byaltering the position ofthe cam is accompanied by great inconvenienceand'delay on account of the ditllcultyand delicacy of the work.

The present invention eliminates the disadvantages above mentioned andpermits the valves to be timed under normal running conditions withoutinterruption of the work,

and with this object in view the inventionconsists in the provision `ofmeans to allow of an adjustment of the cam roller relative to the caminstead of altering the position of the cam itself. The rocking lever,for this purpose, is made in two parts and has two eccentricities ofwhich each may be altered 4independently of the other. By suitablyaltering the eccentricity of the one or the other part, which may bedone while the engine is running, the radial distance, or the tangentialdistance, of the roller from the cam may be independently adjusted asrequired, whereas a suitable adjustment of both Yeccentricities willeiect an alteration of the valve lift as regards stroke as Well as -timeand duration of opening. The working diagram ma thus be convenientlycorrected without t e necessity of stopping the engine. The accompanyingdrawing illustrates the invention by wa of example.

Fig. 1 is a si e elevation of the improved rocking lever arrangement,some minor parts being shown in section.

the working lever is made to consist o Y two parts, namely the rollerarm a and the lifter A portion b, the latter terminating in a forked endin which the former is received. Both Y parts are held to one another bybolts c and d. Within the boss of the rocking lever there islooselyarranged an eccentric bushing e which lits over the valve rockerpin upon which it may be circumferentially adjusted. The said bushing isprovided at its upper portion with aflange extension e1 and 1s adaptedto turn to an extent limited by the slot e2 in the flange in Iwhich isreceived a pin or stud f mounted in the lifter a-rm b. The bushing isheld in relation to the lever by means of a nut g which vis threaded onthe pin f.

An eccentric disc z. is keyed or otherwise i fixed to the aforesaidconnection bolt c and adapted to turn within a cavity of the roller arma so as to adjust the vertical position of the latter. To permit thisadjustment to be made the bore z' of the roller arm a is greater indiameter than the bushing e by an amount which corresponds to the amountof eccentricity of the disc h. `In addition there is a like amount ofclearance between the bolt d in its bolt hole j. To facilitate settingthe roller, the lifter arm b is provided at its top with a graduatedscale 7c, from which the 70 l Fig. 2 is a cross section through thecentre l amount of adjustment of the bushing e and the eccentric disc hmay be observed.

In order, now, to alter the distance from the cam of the roller Z of therocking lever the rigid bolt connection between the bushing e and thelifter arm b must be slackened by loosening the nut g and turning thebushing e upon its pivot to the desired extent and in the directionrequired, the graduated scale n affording a means by which an accurateadjustment may be secured. The eccentric shape of the said bushing willthus cause the centre point of the rocking lever boss to be shifted and,the lifter arm'end o serving as fulcrum, to cause a radial movement ofthe roller Z towards or away from the cam. In this way the lift of theneedle valve as well as the duration of opening may be altered.

' After this adjustment has been carried out the bushin e may again besecured in position byltig tening up theV nut g. This having been done,the connection bolts c and d are slackened and the eccentric disc h,turned as far as required, whereby the roller arm a will be moved withinits enclosing lifter arm in a direction tangential tothe circumferenceof the cam, whereby the time of valve opening will be alteredcorrespondingly.

It will be seen that, by simply slackening a few screw connections andturning the two eccentrics e and h, the position of the roller may bealtered as required and the valve gear timed so as to obtain properworking diagrams.

The invention is mainly designed for use in marine engines, in whichconnection it offers 'unusual advantages, one being that with an engineprovided with these rocking levers` it is no longer necessary tointerrupt the run of the vessel when the valve-timing is to be altered,thus eliminating the dangers resulting from unmanuvreability of the shipduring the time of adjusting the valve gear as well as any waste of timein connection with such work. However, the invention is equally welladapted for use on stationary engines in which very similar advantagesmay be obtained.

What I claim'is:

1. In an internal combustion engine, the combination of a valve, a camfor controlling the movement of the valve, and a lever for actuating thevalve interposed between the valve` and the cam, this lever comprising apair of arms secured together vand pivotally mounted on a single pivot,one of said arms having an end engaging the cam, and means for varyingthe position of said end relative to the cam in two directions,approximately normal to each other.

2. In an internal combustion engine, the combination ofv a valve, a camfor controlling the movement of the valve, and a lever for actuating thevalve interposed between the valve and the cam, this lever comprising apair of arms secured together and pivotally mounted on a single pivot,one of said arms having an end engaging the cam, and independent meanscarried by the arms for varying the position of the said end in radialand tangential directions with. respect to said cam. v

3.*A rocking lever for'internal combustion engine valves comprising thecombination of a pair of arms secured together and mounted on a singlepivot, one of said arms having an end adapted to be acted on by a cam,and means carried by the arms for effecting independent adjustments ofthe camengaging arm relative to said other arm, one of said adjustmentsbeing in a direction radially of said cam, and the other in a directiontangentially of said cam.

4. A rocking lever for internal combustion engines consisting of twoseparate parts, two independently movable eccentric members inconnection with the said parts, a cam roller carried at the end of onepart, valve lifting means at the end of the other part, and a forkedboss to the valve lifting 90 part enclosing the bearing portion of thecam roller carrying part.

5. In a valve actuating gear for internal combustion engines a rockinglever comprising a cam roller carrying arm, a valve lifting armseparately therefrom, means for detachably connecting the two arms, arotatable eccentric bushing in connection with said valve lifting partfor alternating the position of the cam roller in a direction radiallyto thecam, and eccentric means to alter the position of the cam rollerin a direction tangentially to the cam.

6. In a valve actuating gear for internal combustion engines a rockinglever comprising a cam roller carrying arm, a valve lifting arm separatetherefrom, means for detachably connecting the -two arms, eccentricmeans in connection withthe valve lifting arm for altering the positionof the cam roller in a direction radially to the cam, and an eccentricdisc on the rollercarrying arm and rotatable in the valve lifter arm toalter the position of the cam roller tangential to the cam. i

7. In a rocking lever for internal combustion engines, a valve liftingarm having a forked boss, a rotatable eccentric bushing in connectionwith said valve lifting arm, an upwardly extending flange portion tosaid bushing, a slot in said flange portion, a stud carried by the valvelifting arm passing lthrough the said slot, a cam roller carrying todetachably connect hoth arms to one an- In testimony whereof I havehereunto set other, two mutually independent eccentric my hand, in thepresence of two subscribing members to alter the position of the camwitnesses.

roller radially and 'tangentially in relation GUSTAV PIELSTICK. to thecam, and a graduated scale to enable Witnesses: a correct setting vofboth the said eccentric ALEXANDER DE Soro,

members. v ALEXEI PHnIPPoFF.

